[Intel-gfx] [PATCH 1/3] drm/i915: Reject bigjoiner if the pipe doesn't support it

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Check that our crtc can in fact be the bigjoiner master before
we let the modeset proceed with bigjoiner enabled.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 0964b2403e2d..36e547bd0cbe 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -4102,6 +4102,14 @@ static u8 bigjoiner_pipes(struct drm_i915_private *i915)
 		return 0;
 }
 
+static u8 bigjoiner_master_pipes(struct drm_i915_private *i915)
+{
+	u8 pipes = bigjoiner_pipes(i915);
+
+	/* last pipe can not be master */
+	return pipes & (pipes >> 1);
+}
+
 static bool transcoder_ddi_func_is_enabled(struct drm_i915_private *dev_priv,
 					   enum transcoder cpu_transcoder)
 {
@@ -7600,6 +7608,7 @@ static int intel_atomic_check_bigjoiner(struct intel_atomic_state *state,
 					struct intel_crtc_state *old_crtc_state,
 					struct intel_crtc_state *new_crtc_state)
 {
+	struct drm_i915_private *i915 = to_i915(state->base.dev);
 	struct intel_crtc_state *slave_crtc_state, *master_crtc_state;
 	struct intel_crtc *slave_crtc, *master_crtc;
 
@@ -7615,6 +7624,13 @@ static int intel_atomic_check_bigjoiner(struct intel_atomic_state *state,
 	if (!new_crtc_state->bigjoiner)
 		return 0;
 
+	if ((bigjoiner_master_pipes(i915) & BIT(crtc->pipe)) == 0) {
+		drm_dbg_kms(&i915->drm,
+			    "[CRTC:%d:%s] Bigjoiner not available on this pipe\n",
+			    crtc->base.base.id, crtc->base.name);
+		return -EINVAL;
+	}
+
 	slave_crtc = intel_dsc_get_bigjoiner_secondary(crtc);
 	if (!slave_crtc) {
 		DRM_DEBUG_KMS("[CRTC:%d:%s] Big joiner configuration requires "
-- 
2.32.0